Urbanization and Its Ecological Impacts in Zanzibar: A Spatial-Temporal Analysis with Land Change Modeler (1995–2024)
DOI:
https://doi.org/10.54536/ajgt.v4i1.4619Keywords:
Zanzibar, Land Use Land Cover Change, Spectral Separability, Transformed Divergence, Jeffries-MatusitaAbstract
This study examines the urban expansion of Zanzibar from 1995 to 2024, utilizing Landsat satellite imagery to highlight the role of remote sensing in understanding land-use changes and their socio-environmental implications. By employing change detection analysis, land cover classification techniques, and spectral separability assessments, the research quantifies the spatial and temporal dynamics of urban growth. Spectral separability was evaluated using Transformed Divergence (TD) and Jeffries-Matusita (J-M) distance metrics to ensure reliable differentiation between land cover classes, enhancing classification accuracy. The analysis focused particularly on urban Unguja Island and its surroundings, where significant urban sprawl has occurred over the past three decades. Results indicate a dramatic increase in built-up areas, rising from 2,650.5 ha in 1995 to 11,407.2 ha in 2024, corresponding to an overall growth of 330.4%. This urban expansion has come at the expense of natural vegetation, which decreased by 26.3% over the study period. While water bodies have remained relatively stable, the transformation of vegetation into urban land highlights the growing environmental pressure exerted by rapid urbanization. The classification accuracy of the study improved over time, with overall accuracies of 78.33%, 87.22%, and 93.33% for the years 1995, 2009, and 2024, respectively. The findings emphasize the importance of implementing sustainable urban planning and policy interventions to mitigate the adverse effects of urban sprawl on ecological sustainability. Integrating remote sensing data with socio-economic analysis is recommended for developing effective land management strategies in Zanzibar.
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